In a conventional ladder-type surface acoustic wave (SAW) filter, as shown in FIG. 10, series resonators 3, 4, and 5 are connected in series between an input terminal 1 and an output terminal 2, and parallel resonators 6 and 7 are connected to respective ports of the series resonator 4. The parallel resonators 6 and 7 are connected to inductance elements 8 and 9, respectively. The inductance elements 8 and 9 are connected to one end of an inductance element 10. The other end of the inductance element 10 is connected to a grounding terminal 11.
A characteristic profile of the conventional ladder-type SAW filter having the above-described arrangement is shown by a line B in FIG. 4. As shown as the line B, the conventional SAW filter has a wide pass band and has a attenuation profile of an amplitude at both sides of the pass band.
The attenuation profile of the conventional SAW filter is not sufficient particularly at a lower side of the pass band. That is, as shown as the line B in FIG. 4, an attenuation amount tends to decline and then increase at the lower side of the pass band.